Position detection device, lens module, imaging apparatus, and angle sensor apparatus

Abstract

A position detection device includes: a first magnetic field generator generating a first magnetic field; a driver opposed to the first magnetic field generator in a first-axis direction; and a magnetic field sensor detecting the first magnetic field. The driver causes the first magnetic field generator to move in a second-axis direction parallel to a first plane orthogonal to the first-axis direction. The first magnetic field generator is movable in the second-axis direction with respect to the driver and the magnetic field sensor. The driver is spaced from and overlaps a part of the first magnetic field generator in the first-axis direction, and extends across the part of the first magnetic field generator in a third-axis direction parallel to the first plane and orthogonal to the second-axis direction. A center position of the magnetic field sensor in the third-axis direction is different from that of the first magnetic field generator.

What is claimed is: 
     
         1 . A position detection device comprising:
 a first magnetic field generator generating a first magnetic field;   a driver opposed to the first magnetic field generator in a first-axis direction and configured to generate a driving force to thereby cause the first magnetic field generator to move in a second-axis direction parallel to a first plane orthogonal to the first-axis direction; and   a magnetic field sensor configured to detect a magnetic field component, of the first magnetic field, that is parallel to the first plane, wherein   the first magnetic field generator is movable in the second-axis direction with respect to the driver and the magnetic field sensor,   the driver is spaced from and overlaps a part of the first magnetic field generator in the first-axis direction, and extends across the part of the first magnetic field generator in a third-axis direction parallel to the first plane and orthogonal to the second-axis direction, and   a center position of the magnetic field sensor in the third-axis direction is different from a center position of the first magnetic field generator in the third-axis direction.   
     
     
         2 . The position detection device according to  claim 1 , wherein the first magnetic field generator is movable along the second-axis direction between a first position and a second position both inclusive, while remaining in a state of overlapping a part of the driver in the first-axis direction. 
     
     
         3 . The position detection device according to  claim 1 , wherein the driver comprises a second magnetic field generator configured to generate a second magnetic field as the driving force. 
     
     
         4 . The position detection device according to  claim 1 , wherein the first magnetic field generator includes
 a first magnetized region magnetized in a first direction along the first-axis direction, and   a second magnetized region magnetized in a second direction along the first-axis direction, the second direction being opposite to the first direction.   
     
     
         5 . The position detection device according to  claim 4 , wherein the first magnetized region and the second magnetized region are arranged along the second-axis direction. 
     
     
         6 . The position detection device according to  claim 5 , wherein
 the first magnetized region includes a first S pole and a first N pole that are arranged in the first direction, and   the second magnetized region includes a second S pole and a second N pole that are arranged in the second direction.   
     
     
         7 . The position detection device according to  claim 5 , wherein the first magnetized region and the second magnetized region are in contact with each other. 
     
     
         8 . The position detection device according to  claim 3 , wherein
 the first magnetic field generator includes: a first magnetized region magnetized in a first direction along the first-axis direction; and a second magnetized region magnetized in a second direction along the first-axis direction, the second direction being opposite to the first direction,   the second magnetic field generator includes: a first part that is spaced from and overlaps the first magnetized region in the first-axis direction; and a second part that is spaced from and overlaps the second magnetized region in the first-axis direction, and   the first magnetic field generator is movable along the second-axis direction between a first position and a second position both inclusive, while remaining in a state in which the first magnetized region overlaps the first part and the second magnetized region overlaps the second part.   
     
     
         9 . The position detection device according to  claim 8 , wherein
 the driver comprises a coil wound in a plane parallel to the first plane, and   a direction of the second magnetic field to be generated by the first part and exerted on the first magnetized region is opposite to a direction of the second magnetic field to be generated by the second part and exerted on the second magnetized region.   
     
     
         10 . The position detection device according to  claim 5 , wherein
 the first magnetized region and the second magnetized region are at a distance from each other, and   the first magnetic field generator further includes a third magnetized region between the first magnetized region and the second magnetized region, the third magnetized region being magnetized in a third direction along the second-axis direction.   
     
     
         11 . The position detection device according to  claim 5 , wherein
 the first magnetized region and the second magnetized region are at a distance from each other, and   the first magnetic field generator has a space between the first magnetized region and the second magnetized region, or includes an unmagnetized region between the first magnetized region and the second magnetized region.   
     
     
         12 . The position detection device according to  claim 5 , wherein
 the first magnetized region and the second magnetized region are at a distance from each other,   the first magnetized region includes a first opposed surface opposed to the second magnetized region,   the second magnetized region includes a second opposed surface opposed to the first magnetized region, and   all or a part of the first opposed surface and all or a part of the second opposed surface are inclined surfaces or curved surfaces, the inclined surfaces being in parallel in the third-axis direction and inclined with respect to the first plane.   
     
     
         13 . The position detection device according to  claim 3 , wherein
 the second magnetic field generator comprises a coil wound in a plane parallel to the first plane, and   the magnetic field sensor is disposed inside the coil in a plan view as viewed in the first-axis direction.   
     
     
         14 . The position detection device according to  claim 3 , wherein
 the second magnetic field generator comprises a coil wound in a plane parallel to the first plane, and   the magnetic field sensor is disposed outside the coil in a plan view as viewed in the first-axis direction.   
     
     
         15 . The position detection device according to  claim 13 , wherein all or a part of the coil and all or a part of the magnetic field sensor overlap each other in the third-axis direction. 
     
     
         16 . The position detection device according to  claim 13 , wherein
 the coil is provided at a first level parallel to the first plane, and   the magnetic field sensor is at a second level parallel to the first plane and different from the first level.   
     
     
         17 . The position detection device according to  claim 5 , wherein
 the driver comprises a second magnetic field generator configured to generate a second magnetic field as the driving force,   the second magnetic field generator includes a first coil and a second coil that are spaced from each other,   a part of the first coil is opposed to the first magnetized region in the first-axis direction,   a part of the second coil is opposed to the second magnetized region in the first-axis direction, and   the magnetic field sensor is located between the first coil and the second coil in the second-axis direction.   
     
     
         18 . The position detection device according to  claim 17 , wherein the first coil, the second coil, and the magnetic field sensor overlap each other in the second-axis direction. 
     
     
         19 . The position detection device according to  claim 17 , wherein
 the first coil and the second coil are provided at a first level parallel to the first plane, and   the magnetic field sensor is at a second level parallel to the first plane and different from the first level.   
     
     
         20 . The position detection device according to  claim 3 , wherein
 the first magnetic field generator includes a magnetized region including an S pole and an N pole that are arranged along the first-axis direction,   the second magnetic field generator includes a first coil and a second coil that are spaced from each other,   a part of the first coil and a part of the second coil are each opposed to the magnetized region in the first-axis direction, and   the magnetic field sensor is located between the first coil and the second coil in the second-axis direction.   
     
     
         21 . The position detection device according to  claim 1 , wherein a plurality of the magnetic field sensors is arranged in the second-axis direction. 
     
     
         22 . A lens module comprising:
 a first magnetic field generator generating a first magnetic field;   a driver opposed to the first magnetic field generator in a first-axis direction and configured to generate a driving force to thereby cause the first magnetic field generator to move in a second-axis direction parallel to a first plane orthogonal to the first-axis direction;   a magnetic field sensor configured to detect a magnetic field component, of the first magnetic field, that is parallel to the first plane; and   a lens, wherein   the first magnetic field generator and the lens are movable together in the second-axis direction with respect to the driver and the magnetic field sensor,   the driver is spaced from and overlaps a part of the first magnetic field generator in the first-axis direction, and extends across the part of the first magnetic field generator in a third-axis direction parallel to the first plane and orthogonal to the second-axis direction, and   a center position of the magnetic field sensor in the third-axis direction is different from a center position of the first magnetic field generator in the third-axis direction.   
     
     
         23 . An imaging apparatus comprising
 an imaging element, and   a lens module,   the lens module including:   a first magnetic field generator generating a first magnetic field;   a driver opposed to the first magnetic field generator in a first-axis direction and configured to generate a driving force to thereby cause the first magnetic field generator to move in a second-axis direction parallel to a first plane orthogonal to the first-axis direction;   a magnetic field sensor configured to detect a magnetic field component, of the first magnetic field, that is parallel to the first plane; and   a lens, wherein   the first magnetic field generator and the lens are movable together in the second-axis direction with respect to the driver and the magnetic field sensor,   the driver is spaced from and overlaps a part of the first magnetic field generator in the first-axis direction, and extends across the part of the first magnetic field generator in a third-axis direction parallel to the first plane and orthogonal to the second-axis direction, and   a center position of the magnetic field sensor in the third-axis direction is different from a center position of the first magnetic field generator in the third-axis direction.   
     
     
         24 . The imaging apparatus according to  claim 23 , further comprising a processor, wherein
 the lens has an optical axis along the second-axis direction, and   the processor is configured to perform focusing on a subject by causing the driver to generate the driving force and thereby causing the first magnetic field generator and the lens to move along a direction of the optical axis.   
     
     
         25 . The imaging apparatus according to  claim 23 , further comprising a processor, wherein
 the lens has an optical axis along the second-axis direction, and   the processor is configured to perform focusing on a subject by causing the driver to generate the driving force and thereby causing the first magnetic field generator and the lens to move along a plane orthogonal to a direction of the optical axis.   
     
     
         26 . An angle sensor apparatus comprising
 a rotating member, and   a position detection device,   the position detection device including:   a first magnetic field generator provided on the rotating member and generating a first magnetic field;   a driver opposed to the first magnetic field generator in a first-axis direction and configured to generate a driving force to thereby cause the first magnetic field generator and the rotating member to rotate in a rotating direction along the second-axis direction parallel to a first plane orthogonal to the first-axis direction; and   a magnetic field sensor configured to detect a magnetic field component, of the first magnetic field, that is parallel to the first plane, wherein   the first magnetic field generator and the rotating member are rotatable in the rotating direction along the second-axis direction with respect to the driver and the magnetic field sensor,   the driver is spaced from and overlaps a part of the first magnetic field generator in the first-axis direction, and extends across the part of the first magnetic field generator in a third-axis direction parallel to the first plane and orthogonal to the second-axis direction, and   a center position of the magnetic field sensor in the third-axis direction is different from a center position of the first magnetic field generator in the third-axis direction.